A mapping \(\eta :(0,\infty )\times (0,2]\rightarrow (0,1]\)  providing such \(\delta =\eta (r,\epsilon )\)  for given \(r>0\)  and \(\epsilon \in (0,2]\)  is
called modulus of uniform convexity. For more on hyperbolic spaces, we refer
the reader to [1]}.
